Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/02—Induction heating
  • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
  • H05B6/101—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces
  • H05B6/103—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces multiple metal pieces successively being moved close to the inductor
  • H05B6/104—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces multiple metal pieces successively being moved close to the inductor metal pieces being elongated like wires or bands
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/02—Induction heating
  • H05B6/36—Coil arrangements
  • H05B6/362—Coil arrangements with flat coil conductors

Definitions

• the invention relates to a device for inductive cross-field heating of flat metallic material, e.g. of strips and plates, with at least one pair of inductors, which forms an intermediate space for the material to pass through, and the inductors of which each have an iron core which has grooves which run in the transport direction and each have a current conductor, the grooves and conductors of the inductors of an inductor pair in each case
• the mirror image is the same and a method for using the device.
• a device for inductive heating with two conductor systems per inductor is known from PCT / GB 92/02212.
• one conductor system across the width of the metallic material produces an approximately sinusoidal course of the induced current density, the period corresponding to the width of the material.
• a number of adjacent conductors of this conductor system have the current flowing through them in the same direction.
• the width of the Pole is determined by the desired correspondence of period length and width of the good by the latter. This first conductor system thus produces an approximately sinusoidal profile of the temperature in the material to be heated.
• the second conductor system now also produces a sinusoidal course of the induced current density across the width of the material to be heated, albeit albeit offset by about ⁇ / 4 compared to the first conductor system, so that precisely the points of the metallic material are heated most strongly by this second conductor system that were previously minimally warmed by the first conductor system.
• the two conductor systems can be switched sequentially. Working alone in a conductor system would result in a very different temperature distribution and could not be accepted.
• this object is achieved in that the conductors of an inductor each have two switchable conductor systems, each conductor system having conductor sections running in the transport direction, the averaging lines of which are symmetrical to one
• the inductor-centered axis running parallel to the direction of transport is arranged so that the individual poles of the conductor systems can have a maximum of two lines. t ⁇ rn are formed and that one pole of the other conductor system is arranged between the poles of the one conductor system.
• the device is operated in such a way that the two conductor systems are clocked and connected to one another with a time delay.
• the poles can be made narrow, so that the temperature distribution across the width of the metallic material is already very uniform.
• the poles of the second conductor system now lie between the poles of the first conductor system and, with a time delay, produce a maximum density of the induced eddy currents precisely at those points where the first conductor system generated a minimum density. This leads to a smoothing of the temperature.
• the two conductor systems are switched one after the other in time, since if current were applied simultaneously, the efficiency of the inductor would be reduced due to the then short distances between two adjacent conductors through which current flows.
• the sequential connection of the two conductor systems thus causes the density of the inductor lines to be doubled with virtually no loss in the efficiency of the inductor.
• the inductor is constructed essentially symmetrically with respect to an inductor-centered axis pointing in the transport direction, the conditions at the edges of the goods to be heated can be kept the same on both sides even with varying widths of the goods to be heated. If the conductors are not rectilinear, the required symmetry relates to averaging straight lines of the conductor sections which, viewed in the transport direction, run from one end of the inductor to the other.
• the device according to the invention can also be designed such that the individual poles of one conductor system are each formed by two conductors and the poles of the other conductor system are each formed by one conductor.
• the device according to the invention can be designed such that the grooves and conductors of the inductors run in a straight line, in a zigzag or in a wave shape.
• the device according to the invention can be designed such that the cores of inductors are divided into core sections in the transport direction.
• the device according to the invention can also be designed such that the inductors and the material to be heated can be aligned relative to one another in the inductor center.
• the method according to the invention can also be carried out in such a way that the two conductor systems are connected in succession to the same power source.
• the method according to the invention can also be carried out in such a way that the two conductor systems are successively connected to separate current sources.
• the method according to the invention can also be carried out in such a way that the two conductor systems are connected to the respective current source over unequal periods of time.
• the method according to the invention can be carried out in such a way that the two conductor systems are connected to the respective current source at intervals.
• I ⁇ shows 1: a schematic representation of the top view of an inductor according to the invention, both conductor systems each having one conductor per pole, and
• an inductor 1 and the material 2, 3 to be heated are shown in broken lines in two different widths.
• the inductor 1 has a core which is divided into four core sections 4, 5, 6, 7. These core sections 4, 5, 6, 7 have grooves 8 which are inclined in alternating alignment with the direction of transport of the metallic goods 2, 3 indicated by the arrow. In the embodiment, they are zigzag. Conductors 9, 10 of the inductor 1 are arranged in these grooves 8 and consequently likewise run in a zigzag shape.
• the conductor 9 has its own power connections 11, 12 and conductor 10 also has its own power connections 13, 14, so that two mutually independent conductor systems are formed.
• the second line system with the conductor 10 is therefore used, the conductor sections of which, as can be seen in FIG. 1 by way of example on the conductor sections 17, 18, run between the poles of the other conductor 9. Due to this geometrical arrangement of the conductors 9, 10, the maximum heating of the metallic material 2, 3 by the one conductor 9 occurs precisely in the areas of the metallic material 2, 3 in which the other conductor 10 has generated a temperature minimum.
• the two conductor systems with their conductors 9, 10 can be switched separately from one another, they can each be supplied with different powers on average over time. This can e.g. happen by the fact that the duration of the
• Such an averaging line 19 is shown in FIG. 1 for the conductor section 20 of the conductor 9.
• This symmetry requirement which relates not only to the edge region of the inductor 1, is particularly advantageous if the inductor 1, as shown in FIG. 1, is used to heat metallic material 2, 3 of different widths.
• FIG. 2 shows an inductor 21, the core of which, as in the previously described inductor 1, is divided into four sections 22, 23, 24, 25, and in which also grooves 26 are inclined to the direction of transport indicated by the arrow warming good 27 run.
• a conductor system, that of the conductor 29 has two conductor sections per pole, ie two directly adjacent conductor sections, the current direction of which is identical.
• the poles of the conductor 28, which consist of a single conductor section, run between the poles of this conductor 29.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• General Induction Heating (AREA)
• Constitution Of High-Frequency Heating (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=6520428

Family Applications (1)

Country Status (5)

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• 1995
  • 1995-06-13 WO PCT/DE1995/000757 patent/WO1995035013A1/fr not_active Ceased
  • 1995-06-13 EP EP95921684A patent/EP0765591B1/fr not_active Expired - Lifetime
  • 1995-06-13 AT AT95921684T patent/ATE173875T1/de not_active IP Right Cessation
  • 1995-06-13 US US08/750,590 patent/US5818013A/en not_active Expired - Fee Related
  • 1995-06-13 DE DE59504341T patent/DE59504341D1/de not_active Expired - Fee Related

Non-Patent Citations (1)

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